Balancing a water system

[theycallmethefireman]

How do you balance a water system on a chiller or a boiler? That was a question on one of my state license test questions. We hardly ever mess with chillers and no boilers at all.

The possible answers were throttle the water system, trim the impeller, and the 3rd one I cannot remember and the last one was all of the above.


Just curious!!

[jdcsr1]

Throttling the water system would be a good answer for a hydronic hot water system. Assuming an engineered system with properly designed pumps and pipe sizes you would set the flow to the system on the outlet of the pump using something like a triple duty valve. Also balancing valves and circuit setters are used to fine tune hw coils etc. For example, if your system is designed for 300 mbh, you would be pumping around 30 gpm's if the design was 10,000 btu's per gallon per minute. Thats what you would throttle your circuit setter to. Hope this helps.

[duke of earl]

Trimming an impeller does not constitute balancing a system. It is something you do after the system is balanced if needed to match pump performance to system friction loss for the sake of pump energy savings.

[theycallmethefireman]

Thanks for the info!